Cleaning head for blackboard renovators



April l5, 1927.

A. P, BENNINGTON CLEANING HEAD FCR BLAGKBOARD RENOVAIORS Filed April l5, 1925 improvements 'in ALBERT. i. BENNINGTQN, or PHILADELPHIA, rnnnsynvimm.

cumino HEAD Fonisizacmaoann Renovations,

'.My invention relates'to new and useful a'cleaning head forblackboard-.renovatoi-s, which embodies a rotary :i member adap ted to carry interchangeable cleaninr devices and located within a casingjac et w'vhichacts as a conduit for niateri'alv drawn inward by a suction device,

an improvednieans for c andv has for its primar object to provide etachably mounting the cleaning devices, such aspexible abrasive discs, in conjunction with a backing member i .onto the rotating member.'

"Another object of the invention is to prollli receive a oo mpxessble backimd*y ineinbei' and thereby .partially house said backing iijicinbei', .superiinposing a liexible abrasive disc over the backing member 'and clamping said flexible abrasive disc'between the backing 4device detacliably member and a clamping mounted on the iotatingvmember.

ifni'ther object of the invention is.v to

i provide','incombination` a rotating disc having, al cavity therein, a coinpressiblebacking member partially housed in said cavity,

va flexible-discsuperimposed on said backing member and a clnmping ring detachably isc and provided width to overlie mounted on; the .rotatable with a Harige of vsuflicient the backing member so that when the clampingring ie forced home the backing member will be com missed with the flexible disc between said Licking member and the clainping ring so as tobe resiliently lield in posiwhich this invention a'pertainamay undenstend liovv to make an usethe saine, Ivvill describe its construction' in detail, reierring by numerals to the accompanying drawing Fig. 1, is. a longitudinal sectional-.view of a'cleanin'g head for blackboard renovators illustrating the -en'ibodinient of my invention with parts` of saidV cleaning head shown in feleva'tion',v for convenience of illustration. FFig. 2, isa. section at the line 2-2 ,of

il.v :1'- A 'f igny carrying outmy invention as 4here ein- .bodied-,1 Q2 represents a liead'foithe blackthe barrel 16 `exactly like the 'bearing 24',

y Application inea April 15, i925. serial No. 28.213.

board renovator as a whole and includes a casing or jacket 3 constructed of generally tubular formation 'open at botli ends and consisting of a body 4 from one end of vWhich projects a reduced shank 5 and from the op posite end projects the venlarged bell (i vto produce a mouth 7 for the entrance of particles drawn into the Casin or jacket by means of a suitable suction vdgeviceconnected in any suitable manner with the' casiIiO or Jacket as by a flexible tube f or con uit, slipped over the shank 5. The rear wall Soif tlie bell 6 is preferably flared outward or is of 'outwardly divergent. formation 'and -iound desirable said wall may be strengthened in the locality'of said hole b thefor mation of alug .10. Within the vody poi'- tion fl are formed a plurality of longitudinal ribs ll, preferably thi-ee in number, spaced about the inner circumference oi'said bedy portion 4so as to'fornithe passageway's l2 between tlie several ribs as plainly shown in Fig. 2. .In the body portion,l and' preferably in the region. of one of the ribs is formed 'a threaded hole i3 in which is positioned the set screw 14 lior coaction with the annular exterior groove 15 interi'nediate the ends of i for- Vpositioning said barrel lengthwise and holdingl the sume stationary Fi 2.

The barrel 16 is open at its inner end Where it isinternally tli-re'aded as indicated at l? -wliile the outer end. is partially closed by an end wallor inturned liange 18 lin which is provided a hole `19. is located the stub or rigid shaft 2O having a threaded inner end 2l., a threaded outer end 22 and a collar 23 adjacent said outer etl between the; ribs 11, as plainly shown iii -V end, which collar is located inV thev holel 'end of said shaft is mountedv a ball bearing 24 So as to abut the inner i'ace 'of saidco'llar Edin cooperative relation tothe shaft and barrel and as said ball bearing is olf' usual construction including two rings and balls it will not be described in detail. A tubular spacer Washer. 25 sui-rounds the shaft 20 with one end in engagement Wit-li theball bearing 24 While another ball bearing 26,'

surrounds the rigid shaft and engages the opposite end of the tubular spacer washer and these parts of the barrel 16 and the outermost bearing 24 a compressible washer 28 is interposed between said end wall 18 and a metallic washer 29 coacting with the outer face of the bearing 24.

The reference numeral 30 represents a flexible shaft of any well known make or construction to an end of which is xed one end of a tubular connector 31 while the opposite end of said connector is externally threaded for threaded connection with the rigid shaft 20 by means of its threads Z1 and said tubular connector is provided with an external spiral groove 32 which acts as a conveyor to urge any matter outward with relation to the lower end of the barrel 16 as will be hereinafter more fully explained.

The flexible shaft 30 is surrounded by a flexible sheath 33, generally constructed of lutticed or interlaced metal strips and one end of this sheath is fixed to the tubular termina-l 311 having threaded connection, as indicated at 3:3 with the smalleiI end of the reducing coupling 36 which in turn has threaded connection. with the inner end of the barrel 1G by means of its threads 17 and the end of' said reducing coupling which connects with the barrel 16 is preferably reduced in diameter to form the shoulder 37 which will engage the inner end of the barrel 16 and thereby determine the position of the coupling relative to the barrel. The coupling has a bore 38 in which the connector 31 snugly fits and therefore any matter which may attempt to enter the coupling will be carried back into the sheath 16 of .the terminal by means of' the spiral conveying groove 32 as will be obvious.

0n the outer end of' the rigid shaft 20 is fitted the rotating disc 39, clamped solidly against the collar 23 of the shaft by means of a nut 40 screwed onto the threaded end 22 and this rotating disc preferably is provided with a hub 111 which engages the collar 2S. Between the disc, and more particularly its hub, and the end wall or flange 18 ot the barrel is interposed a compressible washer 42, such as a. felt washer, to occupy the space between the end wall 18 and the rotating disc and prevent thel accumulation or entrance of dust or other foreign matter about the working parts.

The rotating disc has a central cavity 43 thereby providing an annular flange 44 at right angles to the main portion ot` the disc and a face of this flange is beveled or inclined as at 45. About the periphery of the rotatingr disc are located a. plurality of spaced radial pins 46.

^ In the cavity 43 is located a compressiblc backing member i7 of suiiicient thickness to project considerabl f beyond the annular flange 44 and said backing member has an aperture 48 for registration with the outer end of the rigid shaft and the nut thereon. A flexible abrasive disc 4t) is placed over the exposed portion of the backing member 47 the same being clamped onto the backing member by means of the clamping ring 50 which includes the annulus 51 to surround the perimeter of the rotatingr disc and im inwardly projecting flange 52 which is ot' sufficient width to project beyond the flange 44- ot' the rotating disc so as to overlap the edge of the backing member and that portion of the edge ot' the abrasive disc in the same region. In order to detachably connect the clam )ing ring to the rotating disc the annulus tiereof is provided with a plurality of inclined slots 53 corresponding in number to the pins L16 and positioned for cooperation therewith so that after the backing member and an abrasive disc are positioued and the clamping ring placed thereovcr so that the entrances to the slots 57i register' with the pins 4G a slight turn of the clamping ring will draw its flange downward or inward so as to compress the outer edge of the backing member 46 and at the same time force the edge of the abrasive disc onto the compressed part ol the hacking member to thus clamp the abrasive disc and backing member on the rotating disc. 1n order to insure holding the clamping ring in position on the rotating disc an edge ot' the annulus wall in the region of each inclined .slot is serrated as at 54.

The llexible backing member 47 must be sufliciently resilient as to be readily compressible and tend to force the abrasive disc outward when the latter is clamped in place so as to keep the serrations 54 in engagement with the pins 4G for holding the clamping ring on the rotating disc and5 also to cause the abrasive disc to enter depressions in the blackboard surface being cleaned.

To place the clamping ring upon the rotating disc or remove it thereform it is necessary to hold said rotating disc stationary which is accomplished by passing the holding rod 55 through the hole 9 in the rear wall of the closing bell and inserting the inner end ol said holding rod in the hole 56 formed in the rotating disc and more particularly in the hub of' said disc, said hole being so arranged as to align with the hole 9 and while l have shown but one hole 5G it will be understood that two or more of these might be provided without departing from the invention.

From the olegoinT description it will be obvious to persons tamiliar with this nrt that when the holding rod 55 is in the posiloo ' [een einem@ the 'held stationar disc. y When the device is shaft" 20. AS the l rotating disc 39 will be d Arelative to the casing or Jacket l3 andft 'at by turning'. the clamping 50 ,in-the proper direction thev letter may be placed upon or removed `from vthe rotating disey whlchivill permit the placement Aremoval 'or renewal of the abrasive in use the holding pin 55 is entirely Aremoved Aandthe rotating -disc -ir'e'volved by s. 'suitable prime mover transmitting its motion through thellexible shaft `30, its connector -31 and the rigid working face of' the abrasive disc is 'at right an' les to theexis of rote'tionthe vcleaning lient? Se blackboard with the axial' center of the head et right ii-gles tothe blackboard sul fece. During the 'elean'in' operetione the dirt, dust, articles of blae vboard andother rdrawn into the .bell of the foreign su 'stances will be,

' 'ofA the suction device` with which said by slightly i jacket is connected, after which it will be carried oil' through the passageways'lZ between the ribs 1l. in Vthe body of the jacket and-then thrii 'h the shaft of said jacket-t0 av jsuitble con uit through which it passes to n. suitable receptacle. v

It is tol be understood' that when the condliit is connected with the jacket the ilexible shaft and its sheath are enclosed bythe conduit. .By removingy the set screw` 14 the casing or jacket Bmny be forcedgbnok over 1e flexible shaft und its sheath a-suicient distance to .obtain 'access 'to the lcoiipling 36,50 that it ma bescrewed'out'of the barllyis has been done the coupling 3b' ri1z1y4be moved away from the barrel distendingtlie flexible shaft and simultaneously compressing the sheath 33 which will makeV connector 3l' accessible so that it maybe removed from the rigid shaft is held againstdislodged and.vv 'eck'et by means 20.y The parte being thusdisconnected the rotating disc and their arated from-.tbc etteralso With-,l

barrel 16 'with the component parts may be se c'iisng -or jacket and vthe drawn from the flexible shaft'. and its comf Ponent parte.

' If it is desired i0 disassembie .the bei- I ings then the nut 40 is removed so-that the rotating disc can be outerend'of-the rigid sha-ft and then, Said rigid, @has with the bearings moet @im be w1thdrawn from the inner end of the bei?. reL` When this has been done tben'ut '2? 'may be removed end the bearings slipped off of the rigid shaft along with washer 25.

Ufcourse I do not wish to be limited to' the .enact details of construction as herein shown as these may be `varied".Within' the limits of the appended claim Without ing from the vspirit of my invention.

Having thus fully described my invention, what' I claim as new und useful isz` A clcaninghead for blackboard renown` disk, a coniprestors comrieing e, rotatable n sible bac ino' member carried by said disk a sheet of abrasive material covering tie`- backing?,r member and extendinvf over s portion ot the disk, pins projecting from the periphery of the disk and a ring for chimping the backingmernber and 4the abrasive material to the disk, said ring having inclinecb slots therein opening out through am edge of the ring, the bottom wall of euch Withdrawn vfrom the se the spacerf;

deportek f f slot -being; corrugated so that when the pinsl enter the slots, they will engage the cor-v rugeted portions and thus hold the ring in afd usted position on the disk.

:ln testimony whereof, I have hereunto eiiixed my signature.

ALBERT P. BENNNGION. 

